System and a method for controlling management processes directed to a link aggregation group

ABSTRACT

A transmission control system for controlling management processes, such as shaping, is presented. The management processes are directed to data streams that are parts of data traffic transmitted via a link aggregation group having egress ports in separate functional entities of a network element. For each data frame of the data traffic, it is detected whether the data frame belongs to any of the data streams. Data frames belonging to none of the data streams are forwarded so that these data frames are distributed between the functional entities according to a link aggregation rule. A management rule is maintained for indicating, for each of the data streams, a stream-specific functional entity that runs each management process directed to the data stream. Each data frame belonging to one of the data streams is forwarded to the appropriate stream-specific functional entity in accordance with the management rule.

FIELD OF THE DISCLOSURE

The disclosure relates generally to controlling data traffic. Moreparticularly, the disclosure relates to a method, to a system, and to acomputer program for controlling management processes, such as shaping,in conjunction with link aggregation. Furthermore, the disclosurerelates to a network element such as a router.

BACKGROUND

In conjunction with data transfer there is often a need to bundle two ormore data links to constitute a link aggregation group “LAG”. In manycases, one or more management processes need to be directed to a datastream that is a part of data traffic that is transmitted via a linkaggregation group having egress ports in multiple functional entities ofa network element. The data traffic may consist of data frames that canbe for example Internet Protocol “IP” packets, Ethernet frames, or someother data entities. The network element can be for example an InternetProtocol “IP” router, a MultiProtocol Label Switching “MPLS” switch, apacket optical switch, an Ethernet switch, and/or a software-definednetworking “SDN” controlled network element. The above-mentionedfunctional entities can be for example line cards or other entities ofthe network element which comprise the egress ports.

The management processes may comprise for example shaping forcontrolling the temporal rate profile of the data stream underconsideration, i.e. to control the transmission rate and/or bursts ofthe data stream. For another example, the management processes maycomprise deep packet inspection “DPI” for monitoring the content of thedata stream. Furthermore, the management processes may compriseintrusion detection for monitoring the integrity of the data stream,e.g. for detecting a situation where unwanted data frames have beenincluded into the data stream by an unauthorized malicious party.

The above-mentioned shaping, for example, can be configured on perVirtual Local Access Network “LAN” level or per MPLS Label Switched Path“LSP” level, and it may happen that a data stream to be shaped andrepresenting a VLAN or a LSP is transmitted via egress ports located inmultiple line cards or other functional entities comprising the egressports. Traditionally, shapers are implemented in functional entitiescomprising the egress ports and this means that the desired shaping ratecan be exceeded if the shaping in each functional entity worksindependently of the shaping in the other functional entities. Forexample, if four functional entities are used for transmitting a datastream to be shaped to be at most 100 Mbps and the shaping rate is setto be 100 Mbps in each of these four functional entities, the sum of thetransmission rates of these functional entities can be up to 400 Mbpswhich is four times too much. On the other hand, if the shaping rate isset to be 25 Mbps in each of these four functional entities, the shapingis too restrictive during time periods when the whole data streamhappens to flow via only one, two, or three of the four functionalentities.

One approach for solving the above-described technical problem is suchthat shapers and/or other management devices located in multiplefunctional entities such as line cards are configured to communicatewith each other so that the aggregate of the sub-streams sent viadifferent ones of the functional entities is treated in an appropriateway. A challenge related to this approach is that data exchange betweenthe shapers and/or other management devices located in the differentones of the functional entities would require a big amount ofshort-delay data traffic between these functional entities. In manycases it is not feasible, or not even possible, to arrange such dataexchange between the functional entities. Another approach for solvingthe above-described technical problem is to carry out the shaping and/orother management processes in a place where the whole data stream underconsideration is present. This place can be for example a switch fabricwhich distributes the data stream to the functional entities. Thisapproach is however problematic with multicast “MC” traffic.Furthermore, in cases where there are many switch fabrics for loadbalancing, we have the problem that the switch fabrics should beconfigured to communicate with each other at a high rate and with asmall delay.

SUMMARY

The following presents a simplified summary in order to provide basicunderstanding of some aspects of various invention embodiments. Thesummary is not an extensive overview of the invention. It is neitherintended to identify key or critical elements of the invention nor todelineate the scope of the invention. The following summary merelypresents some concepts in a simplified form as a prelude to a moredetailed description of exemplifying embodiments of the invention.

In accordance with the invention, there is provided a new transmissioncontrol system for controlling one or more management processes. Eachmanagement process can be for example shaping, deep packet inspection“DPI”, or intrusion detection. The one or more management processes aredirected to one or more data streams that are parts of data traffictransmitted via a link aggregation group “LAG” having egress ports inseparate functional entities, e.g. line cards, of a network element. Atransmission control system according to the invention comprises:

-   -   a detection mechanism for detecting, for each of data frames        belonging to the above-mentioned data traffic, whether the data        frame under consideration belongs to any of the data streams,        and    -   a forwarding-control mechanism for controlling the data frames        belonging to none of the data streams to be forwarded to the        functional entities so that these data frames are distributed        between the functional entities according to a link aggregation        rule related to the link aggregation group.

The forwarding-control mechanism is further configured to:

-   -   maintain a management rule that indicates, for each of the data        streams, a stream-specific functional entity that is one of the        functional entities and is configured to run each of one or more        management processes to be directed to the data stream under        consideration, and    -   control, in accordance with the management rule, the data frames        belonging to one of the data streams to be forwarded to the        stream-specific functional entity related to the one of the data        streams.

As each of the data streams is directed to a functional entity that isrelated to the data stream under consideration, one or more managementprocesses, such as e.g. shaping and/or deep packet inspection and/orintrusion detection, can be directed to the data stream even if the datastream is a part of the data traffic transmitted via the linkaggregation group “LAG” having egress ports in many of the functionalentities. This approach according to the invention is applicable tocases where data streams to be shaped and/or otherwise processed can betransmitted so that none of these data streams needs to be dividedbetween two or more of the functional entities. This is a typical caseon e.g. mobile back-haul where point-to-point VLANs and/or LSPs may betransported over link aggregation interface and via a larger Ethernetnetwork. Thus, the above-presented approach is based on the utilizationof the above described typical case.

In accordance with the invention, there is provided also a new networkelement that can be for example an Internet Protocol “IP” router, amultiprotocol label switching “MPLS” switch, a packet optical switch, anEthernet switch, and/or a software-defined networking “SDN” controllednetwork element. A network element according to the invention comprises:

-   -   functional entities, e.g. line cards, capable of transferring        data between each other, at least one of the functional entities        being capable of receiving data from a data transfer network and        at least two of the functional entities being capable of        transmitting data to the data transfer network and running one        or more management processes directed to one or more data        streams each being a part of data traffic transmitted via a link        aggregation group having egress ports in multiple ones of the        two or more functional entities, and    -   a transmission control system according to the invention for        controlling the one or more management processes.

In accordance with the invention, there is provided also a new methodfor controlling one or more management processes directed to one or moredata streams each being a part of data traffic transmitted via a linkaggregation group having egress ports in multiple functional entities ofa network element. A method according to the invention comprises:

-   -   maintaining a management rule that indicates, for each of the        data streams, a stream-specific functional entity that is one of        the functional entities and is configured to run each of one or        more management processes to be directed to the data stream        under consideration,    -   detecting, for each of data frames belonging to the        above-mentioned data traffic, whether the data frame under        consideration belongs to any of the data streams,    -   controlling the data frames belonging to none of the data        streams to be forwarded to the functional entities so that these        data frames are distributed between the functional entities        according to a link aggregation rule related to the link        aggregation group, and    -   controlling, in accordance with the management rule, the data        frames belonging to one of the data streams to be forwarded to        the stream-specific functional entity related to the one of the        data streams.

In accordance with the invention, there is provided also a new computerprogram for controlling one or more management processes directed to oneor more data streams each being a part of data traffic transmitted via alink aggregation group having egress ports in multiple functionalentities of a network element. A computer program according to theinvention comprises computer executable instructions for controlling aprogrammable processing system to:

-   -   maintain a management rule that indicates, for each of the data        streams, a stream-specific functional entity that is one of the        functional entities and is configured to run each of one or more        management processes to be directed to the data stream under        consideration,    -   detect, for each of data frames belonging to the above-mentioned        data traffic, whether the data frame under consideration belongs        to any of the data streams,    -   control the data frames belonging to none of the data streams to        be forwarded to the functional entities so that these data        frames are distributed between the functional entities according        to a link aggregation rule related to the link aggregation        group, and    -   control, in accordance with the management rule, the data frames        belonging to one of the data streams to be forwarded to the        stream-specific functional entity related to the one of the data        streams.

In accordance with the invention, there is provided also a new computerprogram product. The computer program product comprises a non-volatilecomputer readable medium, e.g. a compact disc “CD”, encoded with acomputer program according to the invention.

A number of exemplifying and non-limiting embodiments of the inventionare described in accompanied dependent claims.

Various exemplifying and non-limiting embodiments of the invention bothas to constructions and to methods of operation, together withadditional objects and advantages thereof, will be best understood fromthe following description of specific exemplifying embodiments when readin connection with the accompanying drawings.

The verbs “to comprise” and “to include” are used in this document asopen limitations that neither exclude nor require the existence of alsoun-recited features.

The features recited in the accompanied dependent claims are mutuallyfreely combinable unless otherwise explicitly stated. Furthermore, it isto be understood that the use of “a” or “an”, i.e. a singular form,throughout this document does not exclude a plurality.

BRIEF DESCRIPTION OF THE FIGURES

Exemplifying and non-limiting embodiments of the invention and theiradvantages are explained in greater detail below with reference to theaccompanying drawings, in which:

FIG. 1 shows a schematic illustration of a network element comprising atransmission control system according to an exemplifying andnon-limiting embodiment of the invention,

FIG. 2 illustrates the operation of a transmission control systemaccording to an exemplifying and non-limiting embodiment of theinvention,

FIG. 3 illustrates the operation of a transmission control systemaccording to another exemplifying and non-limiting embodiment of theinvention, and

FIG. 4 shows a flowchart of a method according to an exemplifying andnon-limiting embodiment of the invention for controlling managementprocesses, such as shaping, in conjunction with link aggregation.

DESCRIPTION OF EXEMPLIFYING AND NON-LIMITING EMBODIMENTS

The specific examples provided in the description below should not beconstrued as limiting the scope and/or the applicability of theaccompanied claims. Lists and groups of examples provided in thedescription below are not exhaustive unless otherwise explicitly stated.

FIG. 1 shows a schematic illustration of a network element 120 accordingto an exemplifying and non-limiting embodiment of the invention. Thenetwork element 120 can be for example an Internet Protocol “IP” router,a multiprotocol label switching “MPLS” switch, a packet optical switch,an Ethernet switch, and/or a software-defined networking “SON”controlled network element. The network element 120 has a modularstructure so that the network element comprises functional entities 121,122, and 123. Furthermore, the network element 120 may comprisefunctional entities which are not shown in FIG. 1. The functionalentities 121-123 are capable of receiving data from a data transfernetwork 124, transferring data between each other, and transmitting datato the data transfer network 124. The data transfer network 124 can befor example a metropolitan area Ethernet. For the sake of illustrativepurposes, it is assumed that the data transfer network 124 is connectedvia data transfer links 127 and 128 to data systems 125 and 126 each ofwhich can be a single network element or a network constituted byinterconnected network elements. Each of the data transfer links 127 and128 can be e.g. a radio link.

In the exemplifying case illustrated in FIG. 1, the functional entities121-123 are line cards of the network element 120. In a general case,each functional entity can be for example a line card, a part of a linecard such as an egress-side of the line card, a single egress port, or agroup of two or more egress ports. It is also possible that a networkelement is a cluster of separate interconnected routers and/or switches,and in this case each router and/or switch can represent a functionalentity.

Each of the functional entities 121-123 of the network element 120comprises a processing system and a memory for running one or more datatransfer protocols and one or more other functionalities of thefunctional entity under consideration. For example, the functionalentity 121 comprises a processing system 130 and a memory 133. The datatransfer protocols may comprise for example the Internet Protocol “IP”,the Ethernet protocol, and/or the multiprotocol label switching “MPLS”.The processing system of each functional entity may comprise one or moreprocessor circuits, each of which can be a programmable processorcircuit provided with appropriate software, a dedicated hardwareprocessor such as for example an application specific integrated circuit“ASIC”, or a configurable hardware processor such as for example a fieldprogrammable gate array “FPGA”. The memory of each functional entity maycomprise one or more memory circuits each of which can be e.g. a randomaccess memory circuit “RAM” or a content access memory circuit “CAM”.The functional entities 121-123 are communicatively interconnected via aconnection module 129 that may comprise for example a backplaneproviding full-mesh connections between the functional entities 121-123,or one or more switch fabrics for communicatively interconnecting thefunctional entities 121-123.

In the exemplifying network element 120 illustrated in FIG. 1, thefunctional entity 121 comprises ingress ports RX_1 and RX_2 and egressports TX_1 and TX_2, the functional entity 122 comprises ingress portsRX_3 and RX_4 and egress ports TX_3 and TX_4, and the functional entity123 comprises ingress ports RX_5 and RX_6 and egress ports TX_5 andTX_6. Furthermore, each functional entity may comprise ingress portsand/or egress ports which are not shown in FIG. 1. As shown in FIG. 1,the egress ports TX_1-TX_5 are connected to data transfer links 136,137, 138, 139, and 140, respectively. Each of these data transfer links136-140 can be for example a fiber link, a copper link, or a radio link.

For the sake of illustrative purposes, it is assumed that the datatransfer links 136-140 are arranged to constitute a link aggregationgroup “LAG” 141 and that a data traffic DT transmitted via the linkaggregation group 141 comprises a data stream DS_1 directed to the datasystem 125 and a data stream DS_2 directed to the data system 126.Furthermore, the data traffic DT may comprise other data trafficcomponents in addition to the above-mentioned data streams DS_1 andDS_2. Furthermore, it is assumed that one or more management processesare to be directed to the data stream DS_1 and one or more managementprocesses are to be directed to the data stream DS_2. The term “datastream” is to be understood in the broad sense so that even a singledata frame can be considered to constitute a data stream, i.e. a datastream does not necessarily comprise a plurality of sequentiallytransferred data frames. Each management process can be for exampleshaping for controlling the temporal rate profile of the data streamunder consideration, deep packet inspection “DPI” for monitoring thecontent of the data stream, or intrusion detection for monitoring theintegrity of the data stream. It is also possible that a managementprocess is a Transmission Control Protocol “TCP” optimization proxyprocess for optimizing TCP-transfer over a transmission path having along delay, e.g. a transmission path comprising a satellite link.

The network element 120 comprises a transmission control systemaccording to an exemplifying and non-limiting embodiment of theinvention for controlling the management processes directed to the datastreams DS_1 and DS_2. The transmission control system comprises adetection mechanism for detecting whether a received data frame belongsto the data traffic DT transferred by the above-mentioned linkaggregation group 141 and for detecting whether the data frame underconsideration belongs to either one of the data streams DS_1 and DS_2.In some exemplifying cases, all the received data frames belong to theabove-mentioned data traffic DT transferred by the link aggregationgroup 141. In these exemplifying cases, the detection mechanism does notneed to detect whether a received data frame belongs to the data trafficDT. The transmission control system comprises a forwarding-controlmechanism for controlling each received data frame to be forwarded to anappropriate one of the functional entities. In this context, the term“forwarding” encompasses also a situation in which a received data frameis transmitted by the same functional entity at which the data frame hasbeen received. For example, it may happen that a data frame is receivedat the functional entity 121 and the forwarding-control mechanismdecides that this data frame is transmitted via the egress port TX_1 orTX_2 of the functional entity 121, i.e. the forwarding-control mechanismcontrols the data frame to be “forwarded” to the functional entity 121.

In the exemplifying network element 120 illustrated in FIG. 1, thedetection mechanism and the forwarding-control mechanism are implementedin a distributed way in the functional entities 121-123 so that thedetection mechanism and the forwarding-control mechanism are arranged toprocess data frames received at these functional entities. The detectionand forwarding-control mechanisms are implemented with the processingsystems and memories of the functional entities 121-123. In FIG. 1, thedetection mechanism is depicted with blocks 101 and theforwarding-control mechanism is depicted with blocks 102. Inexemplifying cases where the connection module 129 comprises one or moreswitch fabrics, the detection and forwarding-control mechanisms can beimplemented in the one or more switch fabrics.

The operation of the transmission control system of the network element120 is described below with reference to FIG. 2. The detection mechanism101 is configured to detect whether a data frame 242 under considerationbelongs to data traffic DT transferred by the link aggregation group141. Furthermore, the detection mechanism 101 is configured to detectwhether the data frame 242 belongs to the data stream DS_1 or DS_2. Thedetection whether the data frame 242 is a part of the data traffic DTcan be based on data related the data frame 242. The data related to thedata frame 242 may comprise for example data read from the data frame242 and/or data that is otherwise related to the data frame 242, e.g. aresult of a routing algorithm such as a result of an IP-routingalgorithm obtained for the data frame 242, or an indicator of theingress port or the functional entity at which the data frame 242 hasbeen received. The detection mechanism 101 can be configured to directfor example a hash function to the data related to the data frame 242and to detect, on the basis of the result of the hash function, whetherthe data frame 242 belongs to the data traffic DT. Hereinafter, it isassumed that the data frame 242 belongs to the data traffic DT. Thedetection whether the data frame 242 belongs to the data stream DS_1 orDS_2 can be based on data read from or otherwise related to the dataframe 242. The data read from the data frame 242 may comprise forexample an Internet Protocol destination address “IP DA”, an InternetProtocol source address “IP SA”, an indicator of a label switched path“LSP” of the multiprotocol label switching “MPLS”, and/or an indicatorof a virtual local access network “VLAN”. The detection whether the dataframe 242 belongs to the data stream DS_1 or DS_2 can be based on forexample the indicator of the VLAN or LSP. In this exemplifying case,data frames representing a given VLAN or LSP constitute one of the datastreams DS_1 and DS_2.

In the exemplifying case illustrated in FIG. 2, the detection mechanism101 is configured to produce an indicator DS which is NULL if the dataframe 242 belongs to none of the data streams DS_1 and DS_2, which is 1if the data frame 242 belongs to the data stream DS_1, and which is 2 ifthe data frame 242 belongs to the data stream DS_2. Furthermore, thedetection mechanism 101 is configured to produce a pointer PTR than canbe for example the result of a hash function for determining whether thedata frame 242 belongs to the data traffic DT that is transferred by thelink aggregation group 141 illustrated in FIG. 1. In this exemplifyingcase, the pointer PTR can be 1, 2, 3, 4 or 5, or the pointer PTR canhave some other predetermined discrete values.

The forwarding-control mechanism 102 is configured to control dataframes which belong to the data traffic DT but neither of the datastreams DS_1 and DS_2 to be forwarded to the functional entities 121-123so that these data frames are distributed between the functionalentities according to a link aggregation rule 203 related to the linkaggregation group 141 illustrated in FIG. 1. In the exemplifying caseillustrated in FIG. 2, the link aggregation rule 203 is implemented witha link aggregation lookup table 205. In an exemplifying situation wherethe data frame 242 belongs to the data traffic DT but neither of thedata streams DS_1 and DS_2, i.e. DS=NULL, the forwarding-controlmechanism 102 retrieves an egress port identifier from the linkaggregation lookup table 205 on the basis of data related to the dataframe 242. In this exemplifying case, the above-mentioned pointer PTRrepresents the data related to the data frame 242. In the exemplifyingsituation shown in FIG. 2, the pointer PTR is 3, and thus the data frame242 is forwarded to the egress port TX_3 that belongs to the functionalentity 122 shown in FIG. 1. The link aggregation rule 203 comprisesadvantageously one or more backup link aggregation lookup tables each ofwhich can be used in lieu of the link aggregation lookup table 205 insituations where one or more of the functional entities cannot be usedfor transmitting data, i.e. the one or more of the functional entitiesis/are faulty or otherwise incapable of transmitting data, one or moreof the data transfer links connected to the one or more functionalentities is/are faulty or otherwise incapable of transferring data,and/or the receiving end is incapable of receiving data from the one ormore functional entities. In the exemplifying case illustrated in FIG.2, the link aggregation rule 203 comprises one backup “BU” linkaggregation lookup table 206 which is used in situations where thefunctional entity 121, i.e. one or both of the egress ports TX_1 andTX_2, cannot be used for transmitting data.

The forwarding-control mechanism 102 is configured to maintain amanagement rule 204 that indicates, for each of the data streams DS_1and DS_2, a stream-specific functional entity that is one of thefunctional entities 121-123 shown in FIG. 1. Each stream specificfunctional entity is configured to run each of one or more managementprocesses, e.g. shaping, to be directed to the data stream underconsideration. The forwarding-control mechanism 102 is configured tocontrol each data frame belonging to the data stream DS_1 or DS_2 to beforwarded to the stream-specific functional entity related to the datastream under consideration. In the exemplifying case illustrated in FIG.2, the management rule 204 is implemented with stream-specificmanagement lookup tables 207 and 210 so that the stream-specificmanagement lookup table 207 relates to the data stream DS_1 and thestream-specific management lookup table 210 relates to the data streamDS_2. The forwarding-control mechanism 102 is configured to retrieve,for each data frame belonging to the data stream DS_1 or DS_2, an egressport identifier from the stream-specific management lookup table 207 or210 corresponding to the data stream under consideration on the basis ofdata related to the data frame under consideration. In this exemplifyingcase, the above-mentioned pointer PTR represents the data related to thedata frame 242. As can be seen from FIG. 2, the stream-specificmanagement lookup table 207 contains egress port identifiers which referto the egress ports TX_1 and TX_2 that belong to the functional entity121 shown in FIG. 1. Thus, the data stream DS_1 is processed, e.g.shaped, and transmitted by the functional entity 121. Correspondingly,the stream-specific management lookup table 210 contains egress portidentifiers which refer to the egress port TX_5 that belongs to thefunctional entity 123 shown in FIG. 1. Thus, the data stream DS_2 isprocessed, e.g. shaped, and transmitted by the functional entity 123. Inan exemplifying situation where the data frame 242 belongs to the datastream DS_1, i.e. DS=1, the forwarding-control mechanism 102 retrievesthe egress port identifier from the stream-specific management lookuptable 207 on the basis of the pointer PTR. In the exemplifying situationshown in FIG. 2, the pointer PTR is 3, and thus the data frame 242 isforwarded to the egress port TX_1 that belongs to the functional entity121 shown in FIG. 1. Correspondingly, in another exemplifying situationwhere the data frame 242 belongs to the data stream DS_2, i.e. DS=2, theforwarding-control mechanism 102 retrieves an egress port identifierfrom the stream-specific management lookup table 210 on the basis of thepointer PTR. In this exemplifying situation, the data frame 242 isforwarded to the egress port TX_5 that belongs to the functional entity123 shown in FIG. 1.

The management rule 204 indicates advantageously, but not necessarily, agroup of backup entities for each of the data streams DS_1 and DS_2.Each of the backup entities is one of the functional entities 121-123.Each of the backup entities related to the data stream DS_1 isconfigured to run each of the one or more management processes, e.g.shaping, to be directed to the data stream DS_1, and each of the backupentities related to the data stream DS_2 is configured to run each ofthe one or more management processes to be directed to the data streamDS_2. The management rule 204 indicates a backup order in which thebackup entities related to the data stream DS_1 are to be used in lieuof the functional entity 121 for processing and transmitting the datastream DS_1, and a backup order in which the backup entities related tothe data stream DS_2 are to be used in lieu of the functional entity 123for processing and transmitting the data stream DS_2. Theforwarding-control mechanism 102 is configured to control, in responseto a switchover to a backup entity, data frames belonging to theappropriate data stream to be forwarded to the backup entity inaccordance with the management rule 204. In the exemplifying caseillustrated in FIG. 2, the management rule 204 comprises stream-specificbackup lookup tables 208 and 209 related to the data stream DS_1 so thatthe stream-specific backup lookup table 208 is a primary backup lookuptable “1^(st) BU” and the stream-specific backup lookup table 209 is asecondary backup lookup table “2^(nd) BU”. The primary backup lookuptable “1^(st) BU” is used in lieu of the stream-specific managementlookup table 207 in cases where the functional entity 121 cannot be usedfor transmitting the data stream DS_1. As can be seen from FIG. 2, theprimary backup lookup table “1^(st) BU” 208 contains egress portidentifiers which refer to the egress ports TX_3 and TX_4 that belong tothe functional entity 122 shown in FIG. 1. Thus, the data stream DS_1 isprocessed, e.g. shaped, and transmitted by the functional entity 122when the functional entity 121 cannot be used. The secondary backuplookup table “2^(nd) BU” is used in lieu of the stream-specificmanagement lookup table 207 and the primary backup lookup table “1^(st)BU” 208 in cases where neither of the functional entities 121 and 122can be used for processing and transmitting the data stream DS_1. As canbe seen from FIG. 2, the secondary backup lookup table “2^(nd) BU” 209contains egress port identifiers which refer to the egress port TX_5that belongs to the functional entity 123 shown in FIG. 1. Thus, thedata stream DS_1 is processed and transmitted by the functional entity123 when the functional entities 121 and 122 cannot be used. Concerningthe data stream DS_2, the management rule 204 comprises stream-specificbackup lookup tables 211 and 212 so that the stream-specific backuplookup table 211 is the primary backup lookup table “1^(st) BU” and thestream-specific backup lookup table 212 is the secondary backup lookuptable “2^(nd) BU”. In the above-presented exemplifying case, two backupfunctional entities are defined for each data stream to be processed. Ina general case, it is possible to define more than two backup functionalentities for each data stream to be processed.

FIG. 3 illustrates the operation of a transmission control systemaccording to another exemplifying and non-limiting embodiment of theinvention. For the sake of illustrative purposes, it is assumed thatdata frames 342 belong to data traffic DT that is transferred via a linkaggregation group “LAG” having egress ports in multiple functionalentities, e.g. line cards, of a network element. The transmissioncontrol system comprises a detection mechanism 301 for detecting whethereach of the data frames 342 belongs to any of data streams DS_1 and DS_2to be processed, e.g. shaped. The transmission control system comprisesa forwarding-control mechanism 302 for controlling those of the dataframes 342 belonging to none of the data streams DS_1 and DS_2 to beforwarded to the functional entities so that these data frames aredistributed between the functional entities according to a linkaggregation rule 303 related to the link aggregation group. Theforwarding-control mechanism 302 is configured to maintain a managementrule 304 that indicates, for each of the data streams DS_1 and DS_2, astream-specific functional entity that is one of the functional entitiesand is configured to run each of one or more management processes to bedirected to the data stream under consideration. The forwarding-controlmechanism 302 is configured to control, in accordance with themanagement rule 304, the data frames belonging to the data stream DS_1or DS_2 to be forwarded to the stream-specific functional entity relatedto the data stream under consideration.

In the exemplifying case illustrated in FIG. 3, the detection mechanism301 is configured to produce an indicator DS which is NULL if a dataframe under consideration belongs to none of the data streams DS_1 andDS_2, which is 1 if the data frame belongs to the data stream DS_1, andwhich is 2 if the data frame belongs to the data stream DS_2.Furthermore, for each data frame, the detection mechanism 301 isconfigured to produce a trigger signal TRIG that orders a Round-Robinmechanism 345 to change its output. The Round-Robin mechanism 345outputs a pointer PTR whose value periodically repeats predetermineddiscrete values such as e.g. 1, 2, 3, 4, and 5. For example, in a casewhere PTR=2, the trigger signal TRIG causes the PTR to be changed to 3,and in a case where PTR=5, the trigger signal TRIG causes the PTR to bechanged to 1.

In the exemplifying case illustrated in FIG. 3, the link aggregationrule 303 is implemented with a link aggregation lookup table 305. In anexemplifying situation where a data frame belongs to the data traffic DTbut neither of the data streams DS_1 and DS_2, i.e. DS=NULL, theforwarding-control mechanism 302 retrieves an egress port identifierfrom the link aggregation lookup table 305 on the basis of data relatedto the data frame. In this exemplifying case, the above-mentionedpointer PTR represents the data related to the data frame. In theexemplifying situation shown in FIG. 3, the pointer PTR is 4, and thusthe data frame is forwarded to the egress port TX_4 that belongs to thefunctional entity 122 shown in FIG. 1. The link aggregation rule 303comprises advantageously one or more backup link aggregation lookuptables each of which can be used in lieu of the link aggregation lookuptable 305 in situations where one or more of the functional entitiescannot be used for transmitting data.

In the exemplifying case illustrated in FIG. 3, the management rule 304is implemented with the link aggregation lookup table 305 and withstream-specific auxiliary lookup tables 307 and 310. The stream-specificauxiliary lookup table 307 relates to the data stream DS_1, and thestream-specific auxiliary lookup table 310 relates to the data streamDS_2. The forwarding-control mechanism 302 is configured to retrieve,for each data frame belonging to the data stream DS_1 or DS_2, apreliminary egress port identifier TX_pre from the link aggregationlookup table 305 on the basis of the pointer PTR and subsequently toretrieve an egress port identifier from the stream-specific auxiliarylookup table corresponding to the data stream under consideration on thebasis of the preliminary egress port identifier TX_pre. As can be seenfrom FIG. 3, the stream-specific auxiliary lookup table 307 containsegress port identifiers which refer to the egress ports TX_1 and TX_2that belong to the functional entity 121 shown in FIG. 1. Thus, the datastream DS_1 is processed, e.g. shaped, and transmitted by the functionalentity 121. Correspondingly, the stream-specific auxiliary lookup table310 contains egress port identifiers which refer to the egress port TX_5that belongs to the functional entity 123 shown in FIG. 1. Thus, thedata stream DS_2 is processed and transmitted by the functional entity123.

In an exemplifying situation where a data frame belongs to the datastream DS_1, i.e. DS=1, the forwarding-control mechanism 302 retrievesthe preliminary egress port identifier TX_pre from the link aggregationlookup table 305 on the basis of the pointer PTR and subsequently 302retrieves the egress port identifier from the stream-specific auxiliarylookup table 307 on the basis of the preliminary egress port identifierTX_pre. In the exemplifying situation shown in FIG. 3, the pointer PTRis 4, and thus the preliminary egress port identifier TX_pre is TX_4 andthus the data frame is forwarded to the egress port TX_2 that belongs tothe functional entity 121 shown in FIG. 1.

The management rule 304 indicates advantageously, but not necessarily, agroup of backup entities for each of the data streams DS_1 and DS_2.Each of the backup entities related to the data stream DS_1 isconfigured to run each of the one or more management processes, e.g.shaping, to be directed to the data stream DS_1, and each of the backupentities related to the data stream DS_2 is configured to run each ofthe one or more management processes to be directed to the data streamDS_2. The management rule 304 indicates a backup order in which thebackup entities related to the data stream DS_1 are to be used in lieuof the functional entity 121 for processing and transmitting the datastream DS_1, and a backup order in which the backup entities related tothe data stream DS_2 are to be used in lieu of the functional entity 123for processing and transmitting the data stream DS_2. Theforwarding-control mechanism 302 is configured to control, in responseto a switchover to a backup entity, data frames belonging to anappropriate data stream to be forwarded to the backup entity inaccordance with the management rule 304. In the exemplifying caseillustrated in FIG. 3, the management rule 304 comprises stream-specificbackup lookup tables 308 and 309 related to the data stream DS_1 so thatthe stream-specific backup lookup table 308 is a primary backup lookuptable “1^(st) BU” and the stream-specific backup lookup table 309 is asecondary backup lookup table “2^(nd) BU” The primary backup lookuptable “1^(st) BU” is used in lieu of the stream-specific managementlookup table 307 in cases where the functional entity 121 cannot be usedfor transmitting the data stream DS_1. As can be seen from FIG. 3, theprimary backup lookup table “1^(st) BU” 308 contains egress portidentifiers which refer to the egress ports TX_3 and TX_4 that belong tothe functional entity 122 shown in FIG. 1. Thus, the data stream DS_1 isprocessed, e.g. shaped, and transmitted by the functional entity 122when the functional entity 121 cannot be used. The secondary backuplookup table “2^(nd) BU” is used in lieu of the stream-specificmanagement lookup table 307 and the primary backup lookup table “1^(st)BU” 308 in cases where neither of the functional entities 121 and 122can be used for transmitting the data stream DS_1. As can be seen fromFIG. 3, the secondary backup lookup table “2^(nd) BU” 309 containsegress port identifiers which refer to the egress port TX_5 that belongsto the functional entity 123 shown in FIG. 1. Thus, the data stream DS_1is processed, e.g. shaped, and transmitted by the functional entity 123when the functional entities 121 and 122 cannot be used. Concerning thedata stream DS_2, the management rule 304 comprises stream-specificbackup lookup tables 311 and 312 so that the stream-specific backuplookup table 311 is the primary backup lockup table “1^(st) BU” and thestream-specific backup lookup table 312 is the secondary backup lookuptable “2^(nd) BU”.

FIG. 4 shows a flowchart of a method for controlling one or moremanagement processes directed to one or more data streams each being apart of data traffic transmitted via a link aggregation group havingegress ports in multiple functional entities of a network element. Themethod comprises the following actions:

-   -   action 401: maintaining a management rule that indicates, for        each of the data streams, a stream-specific functional entity        that is one of the functional entities and is configured to run        each of one or more management processes to be directed to the        data stream under consideration,    -   action 402: detecting, for each of data frames belonging to the        above-mentioned data traffic, whether the data frame under        consideration belongs to any of the data streams,    -   action 403: controlling the data frames belonging to none of the        data streams to be forwarded to the functional entities so that        these data frames are distributed between the functional        entities according to a link aggregation rule related to the        link aggregation group, and    -   action 404: controlling, in accordance with the management rule,        the data frames belonging to one of the data streams to be        forwarded to the stream-specific functional entity related to        the one of the data streams.

A method according to an exemplifying and non-limiting embodiment of theinvention further comprises:

-   -   maintaining the management rule to indicate, for at least the        one of the data streams, a backup entity from among the        functional entities, the backup entity being configured to run        each of the one or more management processes to be directed to        the one of the data streams and being capable of operating in        lieu of the stream-specific functional entity related to the one        of the data streams, and    -   controlling, in response to a switchover to the backup entity,        the data frames belonging to the one of the data streams to be        forwarded to the backup entity.

A method according to an exemplifying and non-limiting embodiment of theinvention further comprises:

-   -   maintaining the management rule to indicate, for at least the        one of the data streams, a group of backup entities from among        the functional entities, each of the backup entities being        configured to run each of the one or more management processes        to be directed to the one of the data streams,    -   maintaining the management rule to indicate a backup order in        which the backup entities are to be used in lieu of the        stream-specific functional entity related to the one of the data        streams, and    -   controlling, in response to a switchover to one of the backup        entities, the data frames belonging to the one of the data        streams to be forwarded to the one of the backup entities.

In a method according to an exemplifying and non-limiting embodiment ofthe invention, the detecting whether the data frame under considerationbelongs to any of the data streams is based on data related to the dataframe under consideration.

In a method according to an exemplifying and non-limiting embodiment ofthe invention, the data related to the data frame under considerationcomprises at least one of the following data items read from the dataframe: an Internet Protocol destination address “IP DA”, an InternetProtocol source address “IP SA”, an indicator of a label switched path“LSP” of multiprotocol label switching “MPLS”, and/or an indicator of avirtual local access network “VLAN”.

In a method according to an exemplifying and non-limiting embodiment ofthe invention, the link aggregation rule is implemented with a linkaggregation lookup table. In this exemplifying case, the methodcomprises retrieving, for each of the data frames belonging to none ofthe data streams, an egress port identifier from the link aggregationlookup table on the basis of the data related to the data frame underconsideration.

In a method according to an exemplifying and non-limiting embodiment ofthe invention, the management rule is implemented with one or morestream-specific management lookup tables. In this exemplifying case, themethod comprises retrieving, for each of the data frames belonging toone of the data streams and on the basis of the data related to the dataframe under consideration, an egress port identifier from thestream-specific management lookup table corresponding to the one of thedata streams.

In a method according to an exemplifying and non-limiting embodiment ofthe invention, the management rule is implemented with theabove-mentioned link aggregation lookup table and with one or morestream-specific auxiliary lookup tables. In this exemplifying case, themethod comprises retrieving, for each of the data frames belonging toone of the data streams and on the basis of the data related to the dataframe under consideration, a preliminary egress port identifier from thelink aggregation lookup table and subsequently retrieving, for the dataframe under consideration and on the basis of the preliminary egressport identifier, an egress port identifier from the stream-specificauxiliary lookup table corresponding to the one of the data streams.

In a method according to an exemplifying and non-limiting embodiment ofthe invention, the one or more management processes comprises at leastone of the following: shaping directed to one of the data streams so asto control the temporal rate profile of the one of the data streams,deep packet inspection directed to one of the data streams so as tomonitor the content of the one of the data streams, and/or intrusiondetection directed to one of the data streams so as to monitor theintegrity of the one of the data streams.

A computer program according to an exemplifying and non-limitingembodiment of the invention comprises computer executable instructionsfor controlling a programmable processing system to carry out actionsrelated to a method according to any of the above-described exemplifyingembodiments of the invention.

A computer program according to an exemplifying and non-limitingembodiment of the invention comprises software modules for controllingone or more management processes directed to one or more data streamseach being a part of data traffic transmitted via a link aggregationgroup having egress ports in multiple functional entities of a networkelement. The software modules comprise computer executable instructionsfor controlling a programmable processing system to:

-   -   maintain a management rule that indicates, for each of the data        streams, a stream-specific functional entity that is one of the        functional entities and is configured to run each of one or more        management processes to be directed to the data stream under        consideration,    -   detect, for each of data frames belonging to the above-mentioned        data traffic, whether the data frame under consideration belongs        to any of the data streams,    -   control the data frames belonging to none of the data streams to        be forwarded to the functional entities so that these data        frames are distributed between the functional entities according        to a link aggregation rule related to the link aggregation        group, and    -   control, in accordance with the management rule, the data frames        belonging to one of the data streams to be forwarded to the        stream-specific functional entity related to the one of the data        streams.

The above-mentioned software modules can be e.g. subroutines orfunctions implemented with a suitable programming language and with acompiler suitable for the programming language and the programmableprocessing system under consideration. It is worth noting that also asource code corresponding to a suitable programming language representsthe computer executable software modules because the source codecontains the information needed for controlling the programmableprocessing system to carry out the above-presented actions and compilingchanges only the format of the information. Furthermore, it is alsopossible that the programmable processing system is provided with aninterpreter so that a source code implemented with a suitableprogramming language does not need to be compiled prior to running.

A computer program product according to an exemplifying and non-limitingembodiment of the invention comprises a computer readable medium, e.g. acompact disc “CD”, encoded with a computer program according to anembodiment of invention.

A signal according to an exemplifying and non-limiting embodiment of theinvention is encoded to carry information defining a computer programaccording to an embodiment of invention.

The specific examples provided in the description given above should notbe construed as limiting the scope and/or the applicability of theappended claims. Lists and groups of examples provided in thedescription given above are not exhaustive unless otherwise explicitlystated.

What is claimed is:
 1. A transmission control system for controlling oneor more management processes directed to one or more data streams eachbeing a part of data traffic transmitted via a link aggregation grouphaving egress ports in multiple functional entities of a networkelement, the transmission control system comprising: a detectionmechanism for detecting, for each of data frames belonging to the datatraffic, whether the data frame under consideration belongs to any ofthe data streams, and a forwarding-control mechanism for controlling thedata frames belonging to none of the data streams to be forwarded to thefunctional entities so that these data frames are distributed betweenthe functional entities according to a link aggregation rule related tothe link aggregation group, wherein the forwarding-control mechanism isconfigured to: maintain a management rule indicating, for each of thedata streams, a stream-specific functional entity, the stream-specificfunctional entity being one of the functional entities and beingconfigured to run each of the one or more management processes to bedirected to the data stream under consideration, and control, inaccordance with the management rule, the data frames belonging to one ofthe data streams to be forwarded to the stream-specific functionalentity related to the one of the data streams, wherein the linkaggregation rule is implemented with a link aggregation lookup table,and the forwarding-control mechanism is configured to retrieve, for eachof the data frames belonging to none of the data streams, an egress portidentifier from the link aggregation lookup table on the basis of datarelated to the data frame under consideration, and wherein themanagement rule is implemented with the link aggregation lookup tableand with one or more stream-specific auxiliary lookup tables, and theforwarding-control mechanism is configured to retrieve, for each of thedata frames belonging to one of the data streams and on the basis ofdata related to the data frame under consideration, a preliminary egressport identifier from the link aggregation lookup table and to retrieve,for the data frame under consideration and on the basis of thepreliminary egress port identifier, an egress port identifier from thestream-specific auxiliary lookup table corresponding to the one of thedata streams.
 2. A transmission control system according to claim 1,wherein the forwarding-control mechanism is configured to: maintain themanagement rule to indicate, for at least the one of the data streams, abackup entity from among the functional entities, the backup entitybeing configured to run each of the one or more management processes tobe directed to the one of the data streams and being capable ofoperating in lieu of the stream-specific functional entity related tothe one of the data streams, and control, in response to a switchover tothe backup entity, the data frames belonging to the one of the datastreams to be forwarded to the backup entity.
 3. A transmission controlsystem according to claim 1, wherein the forwarding-control mechanism isconfigured to: maintain the management rule to indicate, for at leastthe one of the data streams, a group of backup entities from among thefunctional entities, each of the backup entities being configured to runeach of the one or more management processes to be directed to the oneof the data streams, maintain the management rule to indicate a backuporder in which the backup entities are to be used in lieu of thestream-specific functional entity related to the one of the datastreams, and control, in response to a switchover to one of the backupentities, the data frames belonging to the one of the data streams to beforwarded to the one of the backup entities.
 4. A transmission controlsystem according to claim 1, wherein the detection mechanism isconfigured to detect, for each of the data frames of the data traffic,whether the data frame under consideration belongs to any of the datastreams on the basis of data related to the data frame underconsideration.
 5. A transmission control system according to claim 4,wherein the data related to the data frame under consideration comprisesat least one of the following data items read from the data frame: anInternet Protocol destination address, an Internet Protocol sourceaddress, an indicator of a label switched path of multiprotocol labelswitching, an indicator of a virtual local access network.
 6. Atransmission control system according to claim 1, wherein the managementrule is implemented with one or more stream-specific management lookuptables, and the forwarding-control mechanism is configured to retrieve,for each of the data frames belonging to one of the data streams and onthe basis of data related to the data frame under consideration, anegress port identifier from the stream-specific management lookup tablecorresponding to the one of the data streams.
 7. A network element for adata transfer network, the network element comprising: functionalentities capable of transferring data between each other, at least oneof the functional entities being capable of receiving data from the datatransfer network and at least two of the functional entities beingcapable of transmitting data to the data transfer network and runningone or more management processes directed to one or more data streamseach being a part of data traffic transmitted via a link aggregationgroup having egress ports in multiple ones of the two or more functionalentities, and a transmission control system for controlling the one ormore management processes, wherein the transmission control systemcomprises: a detection mechanism for detecting, for each of data framesbelonging to the data traffic, whether the data frame underconsideration belongs to any of the data streams, and aforwarding-control mechanism for controlling the data frames belongingto none of the data streams to be forwarded to the functional entitiesso that these data frames are distributed between the functionalentities according to a link aggregation rule related to the linkaggregation group, wherein the forwarding-control mechanism isconfigured to: maintain a management rule indicating, for each of thedata streams, a stream-specific functional entity, the stream-specificfunctional entity being one of the functional entities and beingconfigured to run each of the one or more management processes to bedirected to the data stream under consideration, and control, inaccordance with the management rule, the data frames belonging to one ofthe data streams to be forwarded to the stream-specific functionalentity related to the one of the data streams, and wherein the one ormore management processes comprises at least one of the following:shaping directed to one of the data streams so as to control a temporalrate profile of the one of the data streams, deep packet inspectiondirected to one of the data streams so as to monitor content of the oneof the data streams, intrusion detection directed to one of the datastreams so as to monitor integrity of the one of the data streams.
 8. Anetwork element according to claim 7, wherein the network element is atleast one of the following: an Internet Protocol IP router, aMultiProtocol Label Switching MPLS switch, a packet optical switch, anEthernet switch, a software-defined networking “SDN” controlled networkelement.
 9. A method for controlling one or more management processesdirected to one or more data streams each being a part of data traffictransmitted via a link aggregation group having egress ports in multiplefunctional entities of a network element, the method comprising:detecting, for each of data frames belonging to the data traffic,whether the data frame under consideration belongs to any of the datastreams, controlling the data frames belonging to none of the datastreams to be forwarded to the functional entities so that these dataframes are distributed between the functional entities according to alink aggregation rule related to the link aggregation group, maintaininga management rule indicating, for each of the data streams, a stream-specific functional entity, the stream-specific functional entity beingone of the functional entities and being configured to run each of theone or more management processes to be directed to the data stream underconsideration, and controlling, in accordance with the management rule,the data frames belonging to one of the data streams to be forwarded tothe stream-specific functional entity related to the one of the datastreams, maintaining the management rule to indicate, for at least theone of the data streams, a backup entity from among the functionalentities, the backup entity being configured to run each of the one ormore management processes to be directed to the one of the data streamsand being capable of operating in lieu of the stream-specific functionalentity related to the one of the data streams, and controlling, inresponse to a switchover to the backup entity, the data frames belongingto the one of the data streams to be forwarded to the backup entity. 10.A method according to claim 9, wherein the detecting whether the dataframe under consideration belongs to any of the data streams is based ondata related to the data frame under consideration.
 11. A methodaccording to claim 10, wherein the data related to the data frame underconsideration comprises at least one of the following data items readfrom the data frame: an Internet Protocol destination address, anInternet Protocol source address, an indicator of a label switched pathof multiprotocol label switching, an indicator of a virtual local accessnetwork.
 12. A method according to claim 9, wherein the management ruleis implemented with one or more streams-specific management lookuptables, and the method comprises retrieving, for each of the data framesbelonging to one of the data streams and on the basis of data related tothe data frame under consideration, an egress port identifier from thestream-specific management lookup table corresponding to the one of thedata streams.
 13. A method according to claim 9, wherein the one or moremanagement processes comprises at least one of the following: shapingdirected to one of the data streams so as to control a temporal rateprofile of the one of the data streams, deep packet inspection directedto one of the data streams so as to monitor content of the one of thedata streams, intrusion detection directed to one of the data streams soas to monitor integrity of the one of the data streams.
 14. A method forcontrolling one or more management processes directed to one or moredata streams each being a part of data traffic transmitted via a linkaggregation group having egress ports in multiple functional entities ofa network element, the method comprising: detecting, for each of dataframes belonging to the data traffic, whether the data frame underconsideration belongs to any of the data streams, controlling the dataframes belonging to none of the data streams to be forwarded to thefunctional entities so that these data frames are distributed betweenthe functional entities according to a link aggregation rule related tothe link aggregation group, maintaining a management rule indicating,for each of the data streams, a stream- specific functional entity, thestream-specific functional entity being one of the functional entitiesand being configured to run each of the one or more management processesto be directed to the data stream under consideration, controlling, inaccordance with the management rule, the data frames belonging to one ofthe data streams to be forwarded to the stream-specific functionalentity related to the one of the data streams, maintaining themanagement rule to indicate, for at least the one of the data streams, agroup of backup entities from among the functional entities, each of thebackup entities being configured to run each of the one or moremanagement processes to be directed to the one of the data streams,maintaining the management rule to indicate a backup order in which thebackup entities are to be used in lieu of the stream-specific functionalentity related to the one of the data streams, and controlling, inresponse to a switchover to one of the backup entities, the data framesbelonging to the one of the data streams to be forwarded to the one ofthe backup entities.
 15. A method according to claim 14, wherein thedetecting whether the data frame under consideration belongs to any ofthe data streams is based on data related to the data frame underconsideration.
 16. A method according to claim 15, wherein the datarelated to the data frame under consideration comprises at least one ofthe following data items read from the data frame: an Internet Protocoldestination address, an Internet Protocol source address, an indicatorof a label switched path of multiprotocol label switching, an indicatorof a virtual local access network.
 17. A method according to claim 14,wherein the one or more management processes comprises at least one ofthe following: shaping directed to one of the data streams so as tocontrol a temporal rate profile of the one of the data streams, deeppacket inspection directed to one of the data streams so as to monitorcontent of the one of the data streams, intrusion detection directed toone of the data streams so as to monitor integrity of the one of thedata streams.
 18. A method for controlling one or more managementprocesses directed to one or more data streams each being a part of datatraffic transmitted via a link aggregation group having egress ports inmultiple functional entities of a network element, the methodcomprising: detecting, for each of data frames belonging to the datatraffic, whether the data frame under consideration belongs to any ofthe data streams, controlling the data frames belonging to none of thedata streams to be forwarded to the functional entities so that thesedata frames are distributed between the functional entities according toa link aggregation rule related to the link aggregation group,maintaining a management rule indicating, for each of the data streams,a stream-specific functional entity, the stream-specific functionalentity being one of the functional entities and being configured to runeach of the one or more management processes to be directed to the datastream under consideration, and controlling, in accordance with themanagement rule, the data frames belonging to one of the data streams tobe forwarded to the stream-specific functional entity related to the oneof the data streams, wherein the link aggregation rule is implementedwith a link aggregation lookup table, and the method comprisesretrieving, for each of the data frames belonging to none of the datastreams, an egress port identifier from the link aggregation lookuptable on the basis of data related to the data frame underconsideration, and wherein the management rule is implemented with thelink aggregation lookup table and with one or more stream-specificauxiliary lookup tables, and the method comprises retrieving, for eachof the data frames belonging to one of the data streams and on the basisof data related to the data frame under consideration, a preliminaryegress port identifier from the link aggregation lookup table andretrieving, for the data frame under consideration and on the basis ofthe preliminary egress port identifier, an egress port identifier fromthe stream-specific auxiliary lookup table corresponding to the one ofthe data streams.
 19. A method according to claim 18, wherein thedetecting whether the data frame under consideration belongs to any ofthe data streams is based on data related to the data frame underconsideration.
 20. A method according to claim 19, wherein the datarelated to the data frame under consideration comprises at least one ofthe following data items read from the data frame: an Internet Protocoldestination address, an Internet Protocol source address, an indicatorof a label switched path of multiprotocol label switching, an indicatorof a virtual local access network.
 21. A method according to claim 18,wherein the one or more management processes comprises at least one ofthe following: shaping directed to one of the data streams so as tocontrol a temporal rate profile of the one of the data streams, deeppacket inspection directed to one of the data streams so as to monitorcontent of the one of the data streams, intrusion detection directed toone of the data streams so as to monitor integrity of the one of thedata streams.
 22. A method for controlling one or more managementprocesses directed to one or more data streams each being a part of datatraffic transmitted via a link aggregation group having egress ports inmultiple functional entities of a network element, the methodcomprising: detecting, for each of data frames belonging to the datatraffic, whether the data frame under consideration belongs to any ofthe data streams, controlling the data frames belonging to none of thedata streams to be forwarded to the functional entities so that thesedata frames are distributed between the functional entities according toa link aggregation rule related to the link aggregation group,maintaining a management rule indicating, for each of the data streams,a stream-specific functional entity, the stream-specific functionalentity being one of the functional entities and being configured to runeach of the one or more management processes to be directed to the datastream under consideration, and controlling, in accordance with themanagement rule, the data frames belonging to one of the data streams tobe forwarded to the stream-specific functional entity related to the oneof the data streams, wherein the one or more management processescomprises at least one of the following: shaping directed to one of thedata streams so as to control a temporal rate profile of the one of thedata streams, deep packet inspection directed to one of the data streamsso as to monitor content of the one of the data streams, intrusiondetection directed to one of the data streams so as to monitor integrityof the one of the data streams.
 23. A method according to claim 22,wherein the detecting whether the data frame under consideration belongsto any of the data streams is based on data related to the data frameunder consideration, and wherein the data related to the data frameunder consideration comprises at least one of the following data itemsread from the data frame: an Internet Protocol destination address, anInternet Protocol source address, an indicator of a label switched pathof multiprotocol label switching, an indicator of a virtual local accessnetwork.